<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<p id="demo">开始段落</p>
		<button type="button" onclick="myFunction()">点一下</button>
		<script>
			function myFunction(){
				document.getElementById("demo").innerHTML = "段落样式被修改。";
			}
		</script>
		
	</body>
</html>
